The purpose of this project is to determine how important GSH transferases are in the conjugation of reaction metabolic intermediates in vivo. We are currently engaged in a search for a compound with the following requirements: 1) The compound must be an effective GSH transferase inhibitor in vivo. 2) It must not deplete GSH from the liver. 3) It must prevent the depletion of GSH caused by hepatotoxins such as acetaminophen. 4) It must not inhibit the cytochrome P-450 drug metabolizing enzymes of the liver. If a compound meeting these requirements can be found, studies to determine whether the compound potentiates the liver toxicity of acetaminophen will be initiated.